This application addresses the broad Challenge Area (15): Translational Science and the specific Challenge Topic, 15-DE-103: Translational Application of Gene Silencing Strategies to Oral and Craniofacial Disorders. Our broad Challenge Area is that despite many studies that have aimed to alleviate the effects of periodontal and endodontic disease there is still an urgent need to improve the oral health of those suffering from oral infectious or inflammatory diseases. Such translational application of gene silencing strategies to oral disorders would save an enormous amount of money and time spent on repairing the severe gum and bone defects that are caused by infectious oral diseases and reduce the degree of suffering they inflict. Our specific Challenge Topic is that that this application addresses to develop a novel treatment that will simultaneously prevent tissue damage and bone loss by reducing the inflammation and bone resorption caused by oral infectious and inflammatory diseases. This study aims to simultaneously reduce inflammation and bone resorption through a single target: Atp6i, a subunit of osteoclast specific proton pump and TIRC7, T cell immune response cDNA 7, an isoform of ATP6i. This study proposes a novel approach for treatment through adeno-associated virus (AAV) knockdown of Atp6i and TIRC7. The recent clinical trials have proved adeno-associated virus (AAV) vector in gene therapy is safe. Since patients with periodontal or endodontic disease suffer from both inflammation-induced tissue damage and bone loss, a single target that can dramatically improve both conditions is ideal. Our lab discovered and characterized Atp6i and we have subsequently demonstrated that this molecule is critical for the extracellular acidification that is necessary for bone loss. Atp6i is furthermore specific to the osteoclast proton pump. In fact, Atp6i is the most appropriate target known for inhibition of bone resorption, since its actions are specific to osteoclast function and it results in complete loss of bone resorptive ability when it is knocked out. Interestingly, TIRC7 is also a regulator of T cell inflammation. Several studies have robustly illustrated that TIRC7 targeting can dramatically help to prevent acute allograft rejection. This dual function of Atp6i gene products makes it an ideal target for knockdown in order to diminish inflammation-induced bone loss. Based on our data and the research of others, we hypothesize that this novel Atp6i RNAi will inhibit both inflammation and bone resorption in oral infectious &inflammatory diseases. We will test this hypothesis through two specific aims. In Aim 1, we will examine the effect of Adeno-associated virus (AAV) mediated Atp6i &TIRC7-RNAi knockdown in T and B cells and osteoclasts in vitro. In Aim 2, we will investigate the effect of adeno-associated virus (AAV) mediated AAV-TIRC7-specific-RNAi knockdown, AAV-Atp6i-specific-RNAi knockdown and AAV-Atp6i &TIRC7-RNAi knockdown in vivo. This innovative and focused study aims to conclusively determine the therapeutic potential of Atp6i and TIRC7 knockdown in the prevention of tissue damage from inflammation and bone loss. Such improvements are imperative since oral diseases that cause tissue damage, bone resorption, and consequent tooth loss are extremely prevalent throughout the world. This research has the potential to save billions of dollars and the critical time to the development of a novel therapeutic for reducing the severity of inflammation induced tissue and bone loss. 1 The proposal addresses to develop a novel treatment that will simultaneously prevent oral tissue damage and bone loss by reducing the inflammation and bone resorption caused by oral infectious and inflammatory diseases using adeno-associated virus (AAV) mediated Atp6i TIRC7 in vivo Gene Silencing. Such translational application of Atp6i TIRC7 gene silencing strategies would save an enormous amount of money and time spent on repairing the severe gum and bone defects. 1